World's first tuberculosis-resistant cows discovered

Online Desk: Designer cows have been created that are resistant to tuberculosis – one of the biggest problems facing dairy farmers around the world.

Badgers are controversially being culled in an effort to stop the bovine form of the disease, which would be unnecessary if cows can be made naturally resistant.

So advances in preventing the disease could be welcomed by farmers whose cattle have to be killed if they catch TB.

Researchers used a 'cut and paste' gene editing technology, known as CRISPR, to insert a new gene into the cow’s genetic codes.

The gene led to no adverse effects on the animal, according to the researchers, but did greatly increase TB resistance.

Scientists at the College of Veterinary Medicine, Northwest A&F University in Shaanxi, China, inserted a gene into the genetic code of calves.

Dr Yong Zhang, lead author of the research, said that insertion of a gene called NNRAMP1 led to disease resistant cattle.

He said: ‘We were then able to successfully develop live cows carrying increased resistance to tuberculosis.

'Importantly, our method produced no off target effects on the cow genetics meaning that the CRISPR technology we employed may be better suited to producing transgenic livestock with purposefully manipulated genetics.’

To carry out the process, the gene was inserted into the nucleus of another kind of bovine cell, called a fibroblast, taken from a cow foetus.